1. Field of the Invention
This invention relates to pipe couplings and more particularly relates to threadless pipe couplings for receiving and retaining the untreated ends of lengths of pipe, such as pipes of steel, cast iron, copper, aluminum, plastic, rubber and the like.
2. Description of the Prior Art
Pipe couplings of various types are well known in the prior art. Several prior art couplings required the ends of the lengths of pipe to be threaded, flanged, outwardly flaired or otherwise deformed. Such couplings were not totally satisfactory as such deformation was costly and time consuming and made assembly in the field more difficult.
To solve the above mentioned problems, the prior art includes a number of couplings requiring no deformation or special treatment of the pipe section ends. Such connectors are generally referred to as "threadless connectors" or "threadless couplings." Examples of such prior art devices may be seen by reference to U.S. Pat. Nos. 1,817,776; 2,073,338; 2,831,711; 3,033,600; 3,804,439 and 3,827,732. These prior art devices were generally improvements as they eliminated the need for threading or otherwise deforming the ends of the pipes to be connected. The prior art devices were, however, not totally satisfactory as they did not provide sufficient tensile strength for certain purposes such as coupling steel or cast iron pipe, they could not easily be produced in variable tensile strength configurations, they were difficult to remove from coupled pipes, they were complicated to assemble to the pipe and/or were not effective when utilized with a section of pipe having a pronounced out-of-round condition on the outer surface thereof.